Problem with IORD and IOWR instructions

Dear all,

I have a qsys system composed of two NIOS that can access a shared memory (data masters are connected to the memory),
when I use the instructions IORD and IOWR I don't obtain the right value
The shared memory is intialised with a hex file that contains tha value 6 at the adress 0

But when NIOS1 does: IORD (SHAREDMEM_BASE, 0x0) I obtain in the console a wrong value : 6c6c6cFc!!!
Also when the first NIOS writes a value at the @0 using IORD and then the NIOS 2 tries to read this value, I obtain a wrong value

I'm using NIOSII SBT 11.1

Please anyone can help me?? is there a functioning example using these two instructions?